Improved tool for turning- centres



rei/tical section bein like bevelled surfaces.

a la

H. D. RICHARDSON, OF EAST HAMPTON, MASSACHUSETTS, AS:

SIGNOR TO HIMSELF ANDJ. WILSON, OF SAME PLACE.

LeamPatmtNo. 89,687, daad 'Ma/y 4, 1869;

IMPROVED TOOL FOR TURNING- CENTRES.

The Schedule referred to in these Letters Patent and making part 0f the Ela-m9- +-4%*- To all whom' 'it may concern:

-Be it known thatrI, H. D. RICHARDSON, of East Hampton, in the county of Hampshire, and Commonwealth of Massachusetts, have invented a new and improved Tool for Turning Centres and other bevelled surfaces; and I do hereby declare that the following is a full, clear, and exact description thereof, reference i plate of a latheand centre, inserted therein, being shown in red lines, and in about the relative position to the tool which they might occupyin a lathe, the

end of the cutting-tool lbeing slightly drawn back from a cutting-position; Y

Figure 2 is an end view, showing the end nearest the face-plate;

Figure 3 is a front elevation of said tool; and

VFigureft is an obliquesectional view, the plane of g indicated by the line X X in iig. 1.

In lathe-work, it is frequently necessary to turn up the bevelled end of that small appliance of a lathe called a centre, which is lirmly inserted in the slightlyconical opening inthe face-plate, as an axis aboutwhich the work in -the lathe revolves, a small hole being drilled or punched in the end of the work, to receive the point of the centre.

These points are continually becoming worn while in use, and have to be re-turned in the lathe, and it is upon the absolute coincidence of the point of the centre with the. axis of the face-plate that the accuracy of the work -which may be turned upon this centre depends.

It is obvious that' the accurate turning of such a tool by hand is a diftcultniatter, and that therewilll be a great liability to carry the point of the centre out of the line of the axis, so long as controlled by the hand and eye.

It is also obvious that even if the apex of the centre should be made axial with the face-plate, the bevel of the angular ends of the different centres, olof the samecentre at different turnings, would vary some-A what, even if turned by the same hand; and, further,

the turning-tool is that any eiort to control the turning-tool so as to produce perfect centres, without a special device for the purpose, would consume much time, and require skilled and expensive labor, with a chance for failure still existing.

The purpose of my invention is to construct a simple .and durable tool, for turning such centres .with mathematical accuracy, and'in'such a manner' as to -prevent the possibility of ialsely locating the point of the centre, and thereby damaging the work which is made to revolve upon it in the lathe.

Other applications of the same tool besides theturning of centres may be made, but the description of the latter operation is believed to convey a complete idea of the application of the device to the turning of other The shank D is -made of the proper Width and thickness to enter the vertical slot in the tool-post gf the lathe upon which it is to be used. i-

The upper sides of A and its edges a e are planed and smoothly finished, to serve as ways for the plate B, which is held down upon A by f and by the piece a', screwed to the under side of B, so that the plate B slides readily along A, like the tail-block of a lathe.

In the outer end of B is formed a socket for the cutting-tool C, which may be of any desired form, and is held in place by the set-screw d.

along the bed-piece A, the latter is provided with a feed-screw H, turned by a winch, h h', and propelling the plate B, by means of the nut N, fastened to the under side of B. A The angle of inclination ofthe sides of the bevelled end of the centre being, say thirty degrees, it is necessary to have some means of setting the bed-piece A at'the same angle to the length of the lathe, so that the cutting-tool O, as it is fed along the bedpiece, by turning the feed-screw H, may move at the same angular inclination to the axis of the faceplate. l

This I eieot by forming that end of A which comes next to the face-plate P angular to the sides of A, the angle being sixty degrees, if the aforesaid incli- It is evident that if a centre is to be turned, the operator has only to set the proper tool O in the tool-socket, and place the shank D in the toolpost of the lathe, 'and then to. slide vthe Whole toward the face-plate P, until the end a'a of the bed A rests squarely against the face-plate, and thus sets the bed at the proper angle, which can then be .preserved through all the movements which may be given to it by the other attachments of the lathe.'

By working the feed-screw H, the tool kO may be moved to and alongthe end of the centre, and must move so as to turn oli' the end of O at the proper angle of thirty degrees, without a possibility of mistake. r

The dimensions of the whole tool may be varied with the work to which it is Ato be applied, the ar- H. D. RICHARDSON.

Witnesses:

`GEO. S. CLARK,

Huso OBEREMPT.

rIo move the plate B and tool C back and forthv nation of -thirty degrees is wanted for the end of the rangement of the coacting parts remaining substanl 

